LITTLE ROCK — The Arkansas Supreme Court has upheld the first-degree murder conviction of a man serving a life sentence in the 2010 stabbing death of a Greenbrier woman.

Justices on Thursday rejected Ronald A. Britton's argument that a lower court erred by failing to grant him a mistrial when he had an apparent manic episode in front of jurors during his trial. The court also rejected Britton's argument that the lower court erred by requiring him to wear a stun belt, shackles and handcuffs after his outburst.

Britton was convicted in Faulkner County in the 2010 stabbing death of 20-year-old Michelle Asher. Lawyers said he cut her throat because he believed she had sexual relations with a black man. Britton was sentenced to life in prison without parole.